18F-PSMA PET/CT and mpMRI: A combined approach for enhanced risk stratification in prostate cancer-a diagnostic accuracy study.

AbstractPrecise diagnosis and grading of prostate cancer (PCa) are essential for determining treatment strategies and predicting patient outcomes. This study is the first to integrate 18F-labeled prostate-specific membrane antigen positron emission tomography/computed tomography (18F-PSMA PET/CT) and multiparametric magnetic resonance imaging (mpMRI) for dual-parameter risk stratification in PCa, evaluating the noninvasive predictive value of 18F-PSMA PET/CT and mpMRI in assessing PCa risk and Ki-67 expression, and providing a novel noninvasive diagnostic approach. We analyzed 84 PCa patients who underwent 18F-PSMA PET/CT and mpMRI before or after biopsy, assessing the maximum standardized uptake value (SUVmax) from PET/CT and minimum apparent diffusion coefficient (ADCmin) from mpMRI. PCa risk was categorized using National Comprehensive Cancer Network (NCCN) guidelines based on clinical T-staging, Gleason score, and prostate-specific antigen, while Ki-67 expression was determined immunohistochemically. High-risk patients exhibited higher SUVmax, SUVmax/ADCmin ratio, prostate-specific antigen, and Ki-67 positivity. The SUVmax/ADCmin ratio demonstrated the strongest predictive value (area under the curve = 0.832), while ADCmin best predicted Ki-67 positivity (area under the curve = 0.719). Logistic regression confirmed that SUVmax, ADCmin, and SUVmax/ADCmin were significantly associated with PCa risk. The combined approach of 18F-PSMA PET/CT and mpMRI enhances PCa risk assessment and predicts Ki-67 expression, indicating potential for disease progression and metastasis. SUVmax/ADCmin is a key imaging parameter for evaluating tumor biology and may guide treatment strategies.